sbase

commit 2277b619be9ae126685b86b7fab694d23be58ccb
parent 37d30f2bd8a7b96ab01f45708f3ef2a9920cc597
Author: FRIGN <dev@frign.de>
Date:   Thu, 22 Jan 2015 20:19:48 +0100

Add support for arbitrary length delimiters in cut(1)

Having multibyte delimiters is not enough. For full flexibility,
the possiblity of cutting input lines with arbitrary length delimiters
is the real deal.
Given this functionality, it only sounds reasonable to also add support
to resolve escapes.
Thanks to Truls Becken for making the suggestion and designing such a
flexible cut(1)-implementation!

Diffstat:
M
cut.1
 | 
2
+-
M
cut.c
 | 
59
+++++++++++++++++++++++++++++++++++++++++------------------

2 files changed, 42 insertions(+), 19 deletions(-)
diff --git a/cut.1 b/cut.1
@@ -67,4 +67,4 @@ utility is compliant with the
 specification.
 .Pp
 The possibility of separating numbers and ranges with a space
-and specifying multibyte delimiters is an extension to that specification.
+and specifying multibyte delimiters of arbitrary length is an extension to that specification.
diff --git a/cut.c b/cut.c
@@ -14,7 +14,7 @@ typedef struct Range {
 
 static Range *list     = NULL;
 static char   mode     = 0;
-static Rune   delim    = '\t';
+static char  *delim    = "\t";
 static size_t delimlen = 1;
 static int    nflag    = 0;
 static int    sflag    = 0;
@@ -73,7 +73,6 @@ seek(const char *s, size_t pos, size_t *prev, size_t count)
 {
 	const char *t;
 	size_t n = pos - *prev, i;
-	Rune r;
 
 	if (mode == 'b') {
 		if ((t = memchr(s, '\0', n)))
@@ -89,12 +88,13 @@ seek(const char *s, size_t pos, size_t *prev, size_t count)
 				break;
 	} else {
 		for (t = (count < delimlen + 1) ? s : s + delimlen; n && *t; ) {
-			for (i = 1; t[i]; i++)
-				if (fullrune(t, i))
+			if (!strncmp(t, delim, delimlen)) {
+				if (!--n && count)
 					break;
-			charntorune(&r, t, i);
-			if (r == delim && !--n && count)
-				break;
+				t += delimlen;
+				continue;
+			}
+			for (i = 1; !fullrune(t, i); i++);
 			t += i;
 		}
 	}
@@ -116,7 +116,7 @@ cut(FILE *fp)
 	while ((len = getline(&buf, &size, fp)) != -1) {
 		if (len && buf[len - 1] == '\n')
 			buf[len - 1] = '\0';
-		if (mode == 'f' && !utfrune(buf, delim)) {
+		if (mode == 'f' && !utfutf(buf, delim)) {
 			if (!sflag)
 				puts(buf);
 			continue;
@@ -139,6 +139,36 @@ cut(FILE *fp)
 	}
 }
 
+static size_t
+resolveescapes(char *s, size_t len)
+{
+	size_t i, off, m;
+
+	for (i = 0; i < len - 1; i++) {
+		if (s[i] != '\\')
+			continue;
+		off = 0;
+
+		switch (s[i + 1]) {
+                case '\\': s[i] = '\\'; off++; break;
+                case 'a':  s[i] = '\a'; off++; break;
+                case 'b':  s[i] = '\b'; off++; break;
+                case 'f':  s[i] = '\f'; off++; break;
+                case 'n':  s[i] = '\n'; off++; break;
+                case 'r':  s[i] = '\r'; off++; break;
+                case 't':  s[i] = '\t'; off++; break;
+                case 'v':  s[i] = '\v'; off++; break;
+		default:   continue;
+		}
+
+		for (m = i + 1; m <= len - off; m++)
+			s[m] = s[m + off];
+		len -= off;
+	}
+
+	return len;
+}
+
 static void
 usage(void)
 {
@@ -151,24 +181,17 @@ int
 main(int argc, char *argv[])
 {
 	FILE *fp;
-	int i;
-	char *m, *d;
 
 	ARGBEGIN {
 	case 'b':
 	case 'c':
 	case 'f':
 		mode = ARGC();
-		m = EARGF(usage());
-		parselist(m);
+		parselist(EARGF(usage()));
 		break;
 	case 'd':
-		d = EARGF(usage());
-		for (i = 1; i <= strlen(d); i++)
-			if (fullrune(d, i))
-				break;
-		charntorune(&delim, d, i);
-		delimlen = i;
+		delim = EARGF(usage());
+		delimlen = resolveescapes(delim, strlen(delim));
 		break;
 	case 'n':
 		nflag = 1;